Iron metabolism in the mononuclear phagocyte system

The maintenance of body iron homeostasis requires the coordination of multiple regulatory mechanisms of iron metabolism. The mononuclear phagocyte system （MPS, composed of monocytes, macrophages, and their precursor cells） is crucial in the maintenance of iron homeostasis. Recycling of iron is carried out by specialized macrophages via engulfment of aged erythrocytes. The iron stores of macrophages depend on the levels of recovered and exported iron. However, the molecular mechanisms underlying iron homeostasis in macrophages are poorly understood. Recent studies characterizing the function and regulation of natural resistance-associated mac- rophage protein 1 （Nrampl）, divalent metal transporter 1 （DMT1）, HLA-linked hemechromatosis gene （HFE）, ferroportin 1 （FPN1）, and hepcidin are rapidly expanding our knowledge on the molecular level of MPS iron handling. These studies are deepening our under- standing about the molecular mechanism of iron homeostasis and iron-related diseases.     

价夸克分布与海夸克分布的核效应

由ｌ－Ａ深度非弹性散射实验数据结合ｐ－Ａ碰撞Ｄｒｅｌｌ－Ｙａｎ截面数据来分别考察束缚核子中价夸克分布与海夸克分布的核效应，提出了一种检验解释ＥＭＣ效应的理论模型的方法。     

癌免疫抑制机制的研究——健康人血浆对肝癌等患者细胞免疫的去抑制作用

临床上癌症患者细胞免疫功能下降的原因,多数认为是由于患者血浆中存在“免疫抑制因子”所致,也有部分认为是T淋巴细胞本身缺陷的原因。那么是不是所有的癌症患者血桨中都有这种“抑制因子”呢?我们采用E——玫瑰花结,淋巴细胞转化联合试验为细胞免疫功能的检测指标,对肝癌、肺癌、胃癌、肠癌及其他癌进行研究。发现:肝癌、肺癌及其他癌患者的血浆确有“免疫抑制因子”,因为健康人血桨对肝癌、肺癌及其他癌患者细胞免疫能起去抑制作用。也就是当患者的血桨与正常人血浆互相交换后,患者细胞免疫功能得到回升,而正常人的细胞免疫功能由于癌症患者血浆的存在而有所下降(统计学上有显著意义)。这说明癌症患者细胞免疫功能下降的原因是相当复杂的。患者血浆中的免疫抑制因子只是一方面的原因,有待于今后继续深入研究。     

Observations of kinetic Alfvén waves by THEMIS near a substorm onset

Low frequency electromagnetic fluctuations in the vicinity of a magnetospheric substorm onset were investigated using simultaneous observations by THEMIS multiple probes in the near-Earth plasma sheet in the magnetotail.The observations indicate that in the vicinity of a substorm onset,kinetic Alfvén waves can be excited in the high-βplasma sheet(β=2μ0nT/B 2 ,the ratio of plasma thermal pressure to magnetic pressure)within the near-Earth magnetotail.The kinetic Alfvén wave has a small spatial scale in the high-βplasma.The parallel electric field accompanying kinetic Alfvén waves accelerates the charged particles along the magnetic field.The kinetic Alfvén waves play an important role in the substorm trigger process,and possibly in the formation of a substorm current wedge.     

Improved zero-sum distinguisher for full round <Emphasis Type="Italic">Keccak-f</Emphasis> permutation

Keccak is one of the five hash functions selected for the final round of the SHA-3 competition,and its inner primitive is a permutation called Keccak-f.In this paper,we observe that for the inverse of the only nonlinear transformation in Keccak-f,the algebraic degree of any output coordinate and the one of the product of any two output coordinates are both 3,which is 2 less than its size of 5.Combining this observation with a proposition on the upper bound of the degree of iterated permutations,we improve the zero-sum distinguisher for the Keccak-f permutation with full 24 rounds by lowering the size of the zero-sum partition from 21590 to 21575.     

因文求义论(续)

所谓"因文求义",就是据上下文即具体语境以求义.从训诂的角度看,语境可分为文旨、文义、文理三端,词语训诂只有合乎这三端,才有可能正确.而要使词语训诂合乎这三端即具体语境,莫过于因文求义.因文求义的依据是语境对词语具有制约功能,其作用则不仅在于考求词义,还可用来校勘文字.     

玉米芯中木糖的提取及测定

本文报道了用氧化－还原滴定法和高压液相色谱法（ＨＰＬＣ）测定木糖,推导出氧化－还原法计算木糖的新公式：木糖含量＝ＶＮＭ÷５式中Ｖ和Ｎ分别为标准高锰酸钾溶液的体积和当量浓度,Ｍ为木糖的分子量。比较氧化－还原和ＨＰＬＣ两种方法的结果,准确度分别为０．９２和０．８２,误差分别为１．０３和０．８２,说明氧化法的准确度高,计算公式合理。     

浅议体操教学中的提示与评价

在体操教学过程中,运用语言来进行提示与评价,可使学生更快的理解动作,建立正确的动作概念,强化动作的正确部分,是掌握动作不可缺少的教法之一,探讨了其在教学中的提示系统与操作、评价的模式。     

不同萱草对SO_2的抗性差异研究

SO2是一种广泛存在的大气污染物.为了探明不同萱草在SO2污染地区的应用价值,采用急性静态熏气方法,研究了美国引种萱草和山西野生萱草对二氧化硫(SO2)的敏感性差异.结果表明:15种不同来源萱草受SO2处理后,对二氧化硫的敏感性均属于中抗及以上,均在极高于常规植物的临界浓度下才显轻微症状,伤害症状均表现为叶尖或者叶缘退绿发黄,叶片轻微萎蔫,随着浓度升高和处理时间延长,向内延伸,只是原有症状的加重,而不出现新症状.当浓度小于0.3 g·m-3时,所有萱草均可以在污染区使用,当浓度高于0.4 g·m-3时,美国萱草M29和M50不适合在极高浓度地区使用.山西野生萱草以平定1号综合抗性最强,美国萱草以M3,M26和M32综合抗性最强.